The AWCC has cultivated the herd since the first 13 bison were brought in from Canada in 2003, in hopes of reestablishing a wood bison population in the U.S. The huge animals, which can weigh up to 2,250 pounds, have been extinct in Alaska for more than 100 years due to overhunting and habitat loss.

This group of rumbling pioneers, who were flown to the release site on a cargo plane, have been outfitted with radio collars and will be closely monitored for the first few years to ensure their nascent herd is thriving.

As the video shows, they were led out of their temporary pens and across the frozen Innoko River by biologist Tom Seaton's snowmobile; the bison were conditioned to follow the snowmobile during their time at AWCC after learning that it handed out food.

The cows, many of whom are pregnant, and young bison will be joined by some of the adult males shortly. Biologists were concerned that placing angry bulls on a plane wasn't the best idea, so they'll be brought in by boat a few months down the road.